1. Field of the Invention
This invention generally relates to respiratory devices and more particularly to a vibrating device and method which assists in breaking up and dislodging accumulated fluids and solids generated in a user's lungs.
2. Description of the Related Art
People who have lung diseases such as cystic fibrosis, bronchiactasis and chronic bronchitis have a difficult time breaking up, dislodging, and expelling mucus and phlegm which develops in the lungs. The presence of this material in the lungs and bronchial and tracheal passages provides an excellent media for growth of bacteria. For treatment of the condition, rotation of antibiotics is used to treat the bacterial infections that result. Postural drainage with induced vibration , percussive therapy and/or the use of a mechanical device such as a flutter valve are often used to help the patient dislodge this mucus material.
Such percussive devices are disclosed in U.S. Pat. Nos. 5,018,517 and 5,451,190 to Liardet. This device is self powered, as are other flutter valve devices available and in use today. That is, the patient exhales into the device which sets up vibrations which feed back through the patient's air ways to break up and dislodge the phlegm. However, this activity is energy consumptive and very draining to the patient. Often, because of a debilitating condition from the effects of pneumonia, for example, the patient has great difficulty blowing into these self powered mechanical devices with sufficient force to achieve any substantive success at dislodging accumulated phlegm.
An active vibratory device is disclosed in U.S. Pat. No. 4,813,403 to Endo. This device comprises an oscillator for generating an electrical signal at a frequency optimally effective for the patient, an audio amplifier, and a transducer connected, through a closed gas volume, to a vibratory diaphragm which is placed against the patient's body, typically the patient's chest or back. The vibration is then transferred from the transducer, through the closed gas volume, to the diaphragm, then to the surface of the patient's body to treat such problems as shoulder discomfort, arthritis, asthmatic spasms and improve blood circulation. The major disadvantage with this approach when the lungs are the target is that by placing the unit on a user's back or chest, the intervening body tissue may substantially attenuate the vibration before it reaches the target area of the lungs and bronchial tubes.
Therefore there is an urgent need for a device that can efficiently and effectively transmit acoustic vibrations to the sites of phlegm buildup in the patient's lungs. There is also a need for a device which does not exhaust the patient's energy during device operation so that this energy can be reserved for effective expulsion of dislodged phlegm.